A spokesman at Renault Samsung Motors, the local unit of Renault S.A., said Sunday the firm doesn't expect any major disruptions for its production, though it noted that Yoosung supplies camshafts for the Renault Samsung's SM5 two-liter gasoline model.

Hyundai and affiliate Kia Motors Corp. source around 70% of their engine parts, including piston rings, cylinder liners and camshafts, from local supplier Yoosung Enterprise Co. Yoosung said on Thursday it had shut its two factories in a dispute with its labor union over pay and a production-shifts system.

Horsepower gains from camshafts are not usually significant (usually one to two HP), but the throttle response and boost to the bottom, mid, and top-end of the power band are the most important power gains.